package/libwebsockets: fix openssl build without threads

Fix the following openssl build failure without threads raised since
bump to version 4.3.1 in commit 3a9cf51ab38b6a3a095241b8e87eab7e5b5bd617 and
https://github.com/warmcat/libwebsockets/commit/471dbf5280b2d0770cdf2803642586cee37a335d:

In file included from /home/buildroot/autobuild/instance-0/output-1/build/libwebsockets-4.3.1/include/libwebsockets.h:661,
                 from /home/buildroot/autobuild/instance-0/output-1/build/libwebsockets-4.3.1/lib/core/./private-lib-core.h:140,
                 from /home/buildroot/autobuild/instance-0/output-1/build/libwebsockets-4.3.1/lib/plat/unix/unix-misc.c:28:
/home/buildroot/autobuild/instance-0/output-1/build/libwebsockets-4.3.1/include/libwebsockets/lws-genhash.h:85:18: error: field 'ctx' has incomplete type
   85 |         HMAC_CTX ctx;
      |                  ^~~

Fixes:
 - http://autobuild.buildroot.org/results/2ae9e3249b6fcc9e6c30e7783e264fc6599e61df

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/libwebsockets/0003-lib-tls-CMakeLists.txt-fix-build-without-threads.patch

@@ -0,0 +1,47 @@
+From c83cf48b9095a6914a0844bec4439763bb0c9138 Mon Sep 17 00:00:00 2001
+From: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+Date: Sat, 28 May 2022 23:15:40 +0200
+Subject: [PATCH] lib/tls/CMakeLists.txt: fix build without threads
+
+openssl can be built without threads resulting in the following build
+failure:
+
+-- Looking for HMAC_CTX_new
+-- Looking for HMAC_CTX_new - not found
+
+[...]
+
+In file included from /home/buildroot/autobuild/instance-0/output-1/build/libwebsockets-4.3.1/include/libwebsockets.h:661,
+                 from /home/buildroot/autobuild/instance-0/output-1/build/libwebsockets-4.3.1/lib/core/./private-lib-core.h:140,
+                 from /home/buildroot/autobuild/instance-0/output-1/build/libwebsockets-4.3.1/lib/plat/unix/unix-misc.c:28:
+/home/buildroot/autobuild/instance-0/output-1/build/libwebsockets-4.3.1/include/libwebsockets/lws-genhash.h:85:18: error: field 'ctx' has incomplete type
+   85 |         HMAC_CTX ctx;
+      |                  ^~~
+
+To fix this build failure, don't unconditionally add pthread if openssl
+has been found through pkg-config as openssl.pc will contain the
+appropriate dependencies (i.e. -lpthread but also -lz or -latomic)
+
+Fixes:
+ - http://autobuild.buildroot.org/results/2ae9e3249b6fcc9e6c30e7783e264fc6599e61df
+
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+[Retrieved from:
+https://github.com/warmcat/libwebsockets/commit/c83cf48b9095a6914a0844bec4439763bb0c9138]
+---
+ lib/tls/CMakeLists.txt | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/lib/tls/CMakeLists.txt b/lib/tls/CMakeLists.txt
+index 559be9abb..a2b78c252 100644
+--- a/lib/tls/CMakeLists.txt
++++ b/lib/tls/CMakeLists.txt
+@@ -311,7 +311,7 @@ endif()
+ if (UNIX AND NOT (${CMAKE_SYSTEM_NAME} MATCHES "QNX"))
+ 	set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} ${CMAKE_DL_LIBS})
+ endif()
+-if ((CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX) AND NOT (${CMAKE_SYSTEM_NAME} MATCHES "QNX"))
++if ((CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX) AND NOT ((${CMAKE_SYSTEM_NAME} MATCHES "QNX") OR PC_OPENSSL_FOUND))
+ 	set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} pthread)
+ endif()
+